| Did you know that in northern countries like the | | | | countries. |
| UK, the earth just a few feet below the surface | | | | There are 3 main elements to a Ground Source |
| keeps a constant temperature of between 11 and | | | | Heat Pump system. The first is the 'ground loop' |
| 12 degrees Centigrade, even in winter? It traps | | | | which is a length of pipe buried in the ground, |
| the heat of the sun, and stores it underground, all | | | | either in a borehole or a horizontal trench. For a |
| year round. A Ground Source Heat Pump | | | | modern detached house you will typically need |
| transfers this heat to your home to provide | | | | two trenches about 40 to 50 metres long to |
| space-heating. Using a compressor (a bit like the | | | | supply enough heat for the house. The ground |
| one in your fridge), it increases this heat to | | | | loop collects the heat from the earth. The second |
| around 45 or 50 degrees, and transfers it to | | | | main element is the heat pump, which is typically |
| radiators or underfloor heating. The heat can also | | | | the same size as a fridge-freezer. This transfers |
| be used to pre-heat your hot water, meaning you | | | | and increases the heat from the ground loop. |
| need less gas or electricity for this also. | | | | Finally you need a distribution system which |
| Because they make use of the renewable energy | | | | basically means underfloor heating or radiators. |
| stored in the ground, Ground Source Heat Pumps | | | | Ground Source Heat Pumps are most suitable for |
| provide one of the most energy-efficient ways of | | | | homes that are well insulated, because otherwise |
| heating buildings. The only energy used by Ground | | | | they can become very expensive to install. The |
| Source Heat Pump systems is the electricity to | | | | cost of a system is directly related to its size, |
| power the pump. Normally a system will deliver 3 | | | | which is in turn driven by the heat it needs to |
| or 4 times as much thermal energy (or heat) as | | | | deliver. If you live in an older building with very |
| the electrical energy used to drive the system. If | | | | high heat loss, this can add substantially to the |
| you can source your electricity from a renewable | | | | capital cost on installing a heat pump. Money spent |
| source such as wind or solar, then your heating | | | | on upgrading wall, floor and loft insulation can save |
| will be completely clean and non-polluting. | | | | a large amount on this capital cost. Unfortunately, |
| Ground Source Heat Pumps have been widely | | | | some older buildings can never be made |
| used for many years in both Europe and North | | | | sufficiently energy efficient to use the modern |
| America. There are now several hundred | | | | heating distribution systems that go with Ground |
| thousand in operation. In Germany, tens of | | | | Source Heat Pumps, such as low temperature |
| thousands of systems are installed each year. | | | | underfloor heating, or low temperature radiators. |
| They typically cost more to install than | | | | You should consult a professional installer if you |
| conventional heating systems. In the UK you | | | | are considering such a system. They will be able |
| should currently expect to pay around | | | | to give you detailed advice on the suitability of |
| £8,000 (plus VAT) or more to heat a | | | | your home. Issues that you should consider are |
| medium-sized house, although government grants | | | | things like whether you have enough space to dig |
| can refund some of this cost (up to £1,200 | | | | the trench for the ground loop, what kind of |
| is available in England and £4,000 in Scotland). | | | | heating distribution system you want (e.g. |
| However, Heat Pumps have very low | | | | underfloor heating), and the size of Heat Pump |
| maintenance costs, and can be expected to | | | | you will need. |
| provide reliable and environmentally-friendly heating | | | | With over 40% of carbon dioxide emissions |
| for over 20 years. | | | | coming from the heating of buildings in countries |
| In a modern, well insulated house, a Ground | | | | like the UK, energy-efficient systems like a |
| Source Heat Pump system can also save you | | | | Ground Source Heat Pump are looking more and |
| money on running costs. It is likely to be cheaper | | | | more attractive. If your home is well insulated, |
| to run than an oil-fired boiler, and less than a third | | | | and you have some outside space like a garden, it |
| of the running cost of electric heating. Currently it | | | | really is worth investigating a system like this to |
| is likely to be just a little bit cheaper than the | | | | help cut your personal contribution to Climate |
| very best of the modern condensing gas boilers, | | | | Change, by making better use of the free heat |
| but gas prices may well rise in the future in many | | | | supplied by the earth. |